An AGC processing portion receives a burst signal of each received frame, and measures its received power level to perform gain control of a variable gain amplifier. Unlike a conventional wireless receiving device, a digital signal from an A/D converter is directly supplied to the AGC processing portion, without passing through an FIR filter. Accordingly, the input timing for the AGC processing portion does not include a delay due to the FIR filter, and an amplitude value can be adjusted to be appropriate from the leading part of each frame, suppressing the occurrence of a reception error due to AGC processing.